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Curing Polymer Clay

Most polymer clays will harden and cure with the appropriate heat and length specified by the manufacturer. Polymer will be soft when first removed from the oven. Once cooled completely it will reach its final hardness. Fully cured polymer clay will be difficult to break. It is always a good idea to create and bake a small test strip before curing your final piece. Polymer clay can be cured in a conventional oven, toaster oven or portable convection oven. Using a small toaster oven may pose some issues as the clay should not be close to the heating element and may cause the clay to burn. All ovens may vary on temperature compared to the actual setting, we recommend using an oven thermometer to check the actual temperature before curing. Using two aluminum backing pans, along with binder clips to secure them together will help keep fumes inside the baking pan.

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Manufacturers Curing Instructions for the Brands We Carry


Fimo Soft, Fimo Effect and Fimo Professional use the same curing temperature and duration. 230°F / 110°C for 30 minutes.

Kato PolyClay™

Block Clay - Cure between 275°F-325°F / 135°C -165°C for 10-30 minutes.
Liquid Polyclay - Cure at 300°F / 150°C for 20 minutes for a matte finish. To create a glossier finish, cure for an additional 10 minutes at 350°F / 177°C, or wave a heat gun over project until desired glossiness is achieved. Do not inhale fumes and never cure above 350°F / 177°C or allow Liquid Polyclay to come in contact with an open flame.


Sculpey III, Primo, Primo Accents and Professional use the same curing temperature and duration. 275°F / 130°C for 15 minutes per 1/4" (6mm) of thickness.